The present invention relates to display devices, and more particularly to maintaining fidelity of color correction information with display devices.
Current computer systems provide individuals with opportunities to produce documents of professional quality, such as with desktop publishing software and graphics software programs. Input/Output (I/O) devices that support image input or output for production of such documents typically include, for example, monitors, printers, scanners, and digital cameras. Usually, a profile of each such I/O device known to the computer system is stored in the system, e.g., in a system folder, to identify particular characteristics of each device. By way of example, profiles typically include color matching information.
Color matching information includes data, such as red, green, and blue (RGB) values and CMYK (cyan, magenta, yellow, black) values, that are associated with objects and text in the document to control how the objects and text will appear when they are displayed and printed. Because RGB and CMYK values, and more particularly, phospher characteristics, including gamma correction and white point values, may differ depending on the particular device involved, color matching is offered as a standard component of some operating systems, such as through a system level API (application program interface) that application programs and device drivers of a computer system call.
Utilization of the profiles normally occurs through the system level API. A device profile typically provides a set of characteristics, such as RGB or CMYK values in the document, to describe the device to which the values are associated and enable the document to be portable, i.e., so that it will have the same appearance when rendered on different devices.
When a display device is color calibrated, as by the creation of a profile, various components of hardware and software are configured to achieve the calibration. For example, the display hardware might be adjusted to provide a particular white point, or the framebuffer hardware might be set to drive the video differently by some combination of altering the gamma table and/or altering the signal.characteristics of the video output to the display. If the configuration then subsequently changes, it is difficult to recreate a previous color environment due to limited capability of maintaining data for a calibrated color environment. Further, other factors that may affect the color environment of a display, such as environmental factors, including ambient lighting conditions, generally cannot be restored.
Accordingly, a need exists for a reliable manner of maintaining color correction information to support recreation of a calibrated color environment. The present invention addresses such a need.
The present invention provides aspects for maintaining and providing a calibrated color environment for display devices of a computer system. In an aspect of an exemplary method, the method includes determining relevant state data, including a framebuffer driver state and a display driver state. The method further includes saving the relevant state data as calibration information for the calibrated color environment. The relevant state data includes information about a display that has an effect on color, such as a framebuffer driver state, a display driver state, and phospher characteristics of the display.
With the present invention, a color calibration state for displays can be fully restored, including restoration of the state of components outside the normal control of a system calibration mechanism. More accurate recreation of a calibrated color environment is achieved efficiently and effectively through the aspects of the present invention. These and other advantages of the aspects of the present invention will be more fully understood in conjunction with the following detailed description and accompanying drawings.